Page:Popular Science Monthly Volume 52.djvu/322

306 proved Teuton, Celt, or Iberian, it is all the same. We have no monopoly of inheritance in it in any case.

I. The European races, as a whole, show signs of a secondary or derived origin; certain characteristics, especially the texture of the hair, lead us to class them as intermediate between the extreme primary types of the Asiatic and the negro races respectively.

From what we have seen of the head form, complexion, and stature of the population of Europe, we might be led to expect that in other physical traits as well this little continent contained all extremes of human variation. We have been surprised, perhaps, at the exceeding diversity of forms occurring within so restricted an area, and in a human group which most of us have perhaps been taught to regard as homogeneous. One physical characteristic alone affords justification for this hypothesis of ethnic homogeneity. This is the form and texture of the hair. Only in this respect, not in color, the hair is quite uniform all over Europe, and even far into Hindustan, where Aryan languages have migrated. At the same time, however, this texture in itself indicates a secondary origin—that is to say, it denotes a human type derived from the crossing of others which we may class as primary. The population of Europe, in other words, should be numbered among the secondary races of the earth. What its constituent elements may have been we shall discuss somewhat later.

The two extremes of hair texture in the human species are the crisp curly variety so familiar to us in the African negro; and the stiff, wiry, straight hair of the Asiatic and the American aborigines. These traits are exceedingly persistent; they persevere oftentimes through generations of ethnic intermixture. It has been shown by Pruner Bey and others that this outward contrast in texture is due to, or at all events coincident with, real morphological differences in structure. The curly hair is almost always of a flattened, ribbon-like form in cross section, as examined microscopically; while, cut squarely across, the straight hair more often inclines to a fully rounded or cylindrical shape. It may be coarse, or fine, or of any color, but the texture remains quite constant in the same individual and the same race. Moreover, this peculiarity in cross section may often be detected in any crossing of these extreme types. The result of such intermixture is to impart a more or less wavy appearance to the hair, and to produce a cross section intermediate between a flattened oval and a circle. Roughly speaking, the more pronounced the flatness, the greater is the tendency toward waviness or curling, and the reverse.

Our map herewith represents the geographical distribution of these several varieties of hair texture among the races of the earth.